The first European explorers to visit Louisiana came in 1528 when a Spanish expedition led by Panfilo de Narváez located the mouth of the Mississippi River. In 1542, Hernando de Soto's expedition skirted to the north and west of the state and then followed the Mississippi River down to the Gulf of Mexico in 1543. Then Spanish interest in Louisiana lay dormant. In the late 17th century, French expeditions, which included sovereign, religious and commercial aims, established a foothold on the Mississippi River and Gulf Coast. With its first settlements, France lay claim to a vast region of North America and set out to establish a commercial empire and French nation stretching from the Gulf of Mexico to Canada.
In 1682, the French explorer Robert Cavelier de La Salle named the region Louisiana to honor France's King Louis XIV. The first permanent settlement, Fort Maurepas (at what is now Ocean Springs, Mississippi, near Biloxi), was founded by Pierre Le Moyne d'Iberville, a French military officer from Canada, in 1699. By then the French had also built a small fort at the mouth of the Mississippi at a settlement they named La Balise (or La Balize), "seamark" in French. By 1721 they built a 62-foot (19 m) wooden lighthouse-type structure to guide ships on the river.
The French colony of Louisiana originally claimed all the land on both sides of the Mississippi River and north to French territory in Canada. The following States were part of Louisiana: Louisiana, Mississippi, Arkansas, Oklahoma, Missouri, Kansas, Nebraska, Iowa, Illinois, Indiana, Michigan, Wisconsin, Minnesota, North Dakota, South Dakota.
France ceded most of its territory to the east of the Mississippi to Great Britain in the aftermath of Britain's victory in the Seven Years' War or French and Indian War, as it was known in North America. It retained the area around New Orleans and the parishes around Lake Pontchartrain. The rest of Louisiana became a colony of Spain after the Seven Years' War by the Treaty of Fontainebleau of 1763.
In 1765, during the period of Spanish rule, several thousand French-speaking refugees from the region of Acadia (now Nova Scotia, New Brunswick, and Prince Edward Island, Canada) made their way to Louisiana following British expulsion after the Seven Years' War. They settled chiefly in the southwestern Louisiana region now called Acadiana. The Spanish, eager to gain more Catholic settlers, welcomed the Acadian refugees. Cajuns descend from these Acadian refugees.
Spanish Canary Islanders, called Isleños, emigrated from the Canary Islands of Spain to Louisiana under the Spanish crown between 1778 and 1783.
In 1800, France's Napoleon Bonaparte acquired Louisiana from Spain in the Treaty of San Ildefonso, an arrangement kept secret for two years.
Thomas Jefferson, third President of the United States, was disturbed by Napoleon's plans to re-establish French colonies in America. With the possession of New Orleans, Napoleon could close the Mississippi to U.S. commerce at any time. Jefferson authorized Robert R. Livingston, U.S. Minister to France, to negotiate for the purchase of the City of New Orleans, portions of the east bank of the Mississippi, and free navigation of the river for U.S. commerce. Livingston was authorized to pay up to $2 million.
An official transfer of Louisiana to French ownership had not yet taken place, and Napoleon's deal with the Spanish was a poorly kept secret on the frontier. On October 18, 1802, however, Juan Ventura Morales, Acting Intendant of Louisiana, made public the intention of Spain to revoke the right of deposit at New Orleans for all cargo from the United States. The closure of this vital port to the United States caused anger and consternation. Commerce in the west was virtually blockaded. Historians believe that the revocation of the right of deposit was prompted by abuses of the Americans, particularly smuggling, and not by French intrigues as was believed at the time. President Jefferson ignored public pressure for war with France, and appointed James Monroe a special envoy to Napoleon, to assist in obtaining New Orleans for the United States. Jefferson also raised the authorized expenditure to $10 million.
However, on April 11, 1803, French Foreign Minister Talleyrand surprised Livingston by asking how much the United States was prepared to pay for the entirety of Louisiana, not just New Orleans and the surrounding area (as Livingston's instructions covered). Monroe agreed with Livingston that Napoleon might withdraw this offer at any time (leaving them with no ability to obtain the desired New Orleans area), and that approval from President Jefferson might take months, so Livingston and Monroe decided to open negotiations immediately. By April 30, they closed a deal for the purchase of the entire 828000 square mile Louisiana territory for 60 million Francs (approximately $15 million). Part of this sum was used to forgive debts owed by France to the United States. The payment was made in United States bonds, which Napoleon sold at face value to the Dutch firm of Hope and Company, and the British banking house of Baring, at a discount of 87 1/2 per each $100 unit. As a result, France received only $8,831,250 in cash for Louisiana.